Recommended Articles

Colorado makes legal peace with Cotter Corp. in push for mine cleanup

Colorado has made legal peace with Cotter Corp. in a push for quicker cleanup of a mine leaking uranium into a creek that reaches a Denver Water reservoir.

The latest test data show that highly toxic water in the Schwartzwalder mine's main shaft seeps underground into Ralston Creek, which flows to Ralston Reservoir.

A settlement deal requires Cotter to pump and treat millions of gallons of water and lower the level to 150 feet below the top of that 2,000-foot-deep shaft. This is intended to prevent uranium — in concentrations up to 1,000 times the health standard — from contaminating water supplies.

Cotter also must provide $3.5 million in financial assurance money to ensure cleanup of the mine west of Denver is done and pay a civil penalty of $55,000. Another $39,000 in penalties is to be waived.

The deal, approved by state regulators, ends Cotter's lawsuits challenging state orders to clean up the mine and the creek. A state judge ruled in favor of regulators and Cotter appealed the decision.

"We're happy to see Cotter rolling up its sleeves and getting to work," said Loretta Pineda, director of Colorado's Division of Reclamation, Mining and Safety. "It's critical that the remedy at the Schwartzwalder site move forward to reduce pollution in Ralston Creek."

Denver Water officials are reviewing Cotter's plans.

Advertisement

"We support the resolution reached between the Mined Land Reclamation Board and Cotter Corporation to initiate immediate mine dewatering," utility spokeswoman Stacy Chesney said. "Our current treatment process removes uranium at the present levels in the raw water, so our drinking water is safe."

Cotter officials couldn't be reached.

For more than two years after contamination of Ralston Creek was made public, Cotter defied state orders to clean up Schwartzwalder — once the nation's largest underground uranium mine, producing 17 million pounds of uranium for nuclear weapons and power plants. Cotter closed the mine in 2000 and water-treatment facilities were dismantled.

This year, Cotter began dealing with the problem by rerouting Ralston Creek through an 18-inch pipe running 4,000 feet around the mine. Cotter officials contend that, while underground pathways may carry uranium to the creek, pumping toxic water out of the mine makes no sense and could cost more than $10 million because groundwater would continue to fill up the mine shaft and turn toxic through contact with exposed minerals.

Cotter favors keeping the highly toxic water inside the mine shaft and treating it there. They propose to mix molasses and alcohol into uranium-laced water to feed bacteria already in the mine shaft — bacteria that could bond with uranium and separate it from water so that it could settle deep underground.

But water tests done after rerouting of the creek "made it immediately evident that the mine pool was leaking out" to the creek, where uranium concentrations remain around 30 parts per billion, state environmental protection specialist Tony Waldron said.

The rerouting is not intended to be permanent, and Cotter is to submit a long-term plan for review by state regulators.

Settling legal disputes "allows us to work more closely with the company," Pineda said. "We're working toward mitigation and reclamation rather than litigation."